cocci: apply the "pretty.h" part of "the_repository.pending"

Apply the part of "the_repository.pending.cocci" pertaining to
"pretty.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

fmt-merge-msg.c

@@ -385,7 +385,8 @@ static void shortlog(const char *name,
 		if (subjects.nr > limit)
 			continue;
 
-		format_commit_message(commit, "%s", &sb, &ctx);
+		repo_format_commit_message(the_repository, commit, "%s", &sb,
+					   &ctx);
 		strbuf_ltrim(&sb);
 
 		if (!sb.len)